Influence of temperature inhomogeneity and trap charge on current imbalance of SiC MOSFETs

For SiC MOSFETs, either multi-chip modules or multiple discrete devices need to be connected in parallel to achieve high current capacities. However, the current imbalance that occurs in parallel applications can reduce device reliability. This paper focused on the effects of both temperature inhomogeneity and gate trap charge on the current imbalance behavior of SiC MOSFETs, and it also presented a comparison study of the effects of threshold voltage differences on the current inhomogeneity. Finally, the effects of the three factors above on the current inhomogeneity characteristics of SiC MOSFETs were compared in terms of their voltage and time dimensions. The results show that the percentage of the drain-source current imbalance due to temperature inhomogeneity for static processes can be maintained consistently at more than 10%. For dynamic processes, the percentage of the drain-source current imbalance due to temperature inhomogeneity can similarly exceed 10%.